Sensorless motor drives are used in a variety of applications, particularly where providing position and/or speed sensors directly at a motor load is difficult or impractical. For example, electric submersible pumps (ESPs) and progressive cavity pumps (PCPs) are used in oil pumps and other applications in which lengthy cables are used to connect the motor drive apparatus to a driven pump motor. In certain applications, a step-up transformer may be used to boost the motor drive output voltage, allowing use of a low-voltage drive to power a medium voltage induction motor, and/or to reduce I2R losses and facilitate use of a smaller diameter cable wire for long cable runs between the motor drive and the driven motor. Certain applications also employ sine wave filters, such as LC filters or other output filters in order to suppress reflected wave voltage spikes associated with pulse width modulated (PWM) variable frequency drives. In some situations, however, such pump motors may spin in an uncontrollable fashion, typically in a direction opposite to the normal pumping direction due to back flow of fluid. For example, a pump motor may be stopped for some reason while a certain amount of fluid is above the pump within an oil well, and the pressure of the previously pumped fluid rotates the motor in the reverse direction. In these circumstances, it is desirable to restart the motor in the positive pumping direction in an efficient and expeditious manner in order to conserve the pumping work that has already been done by limiting the amount of fluid draining back down the well. However, it is often difficult to resume controlled operation of a motor which is spinning in an uncontrolled fashion, and reversal at low speeds and through zero is difficult due to the intervening transformer between the motor drive and the pump motor. Accordingly, there is need for improved motor drive apparatus and techniques for speed reversal control.